You can learn to design printables with free options like Canva, or Paint. These programs are fine for basic designs, but can be very limiting. If you would like completely custom designs, programs like Adobe Photoshop and Illustrator are excellent.
Handing out physical flyers is still a tried-and-true advertising technique that works for all kinds of businesses. From real estate to fashion, you'll find several customizable designs for a variety of needs.